JP3757298B2 - Plug-in fuse female terminal - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a female terminal of a plug-in fuse.
[0002]
[Prior art]
Conventionally, there are many types of female terminals in a plug-in fuse, but generally, a bulging portion is formed in the center of a tongue piece insertion space of a female terminal provided with a pair of opposing conductive plates. The inlet side of the spring plate is fixed so as to face the bulging portion of the formed spring plate, and the distal end of the spring plate is electrically conductive plate material by the pressing force to the bulging portion when the tongue-shaped male terminal is inserted It slides on the flat inner surface.
[0003]
On the other hand, although it is not a fuse, it is disclosed in Japanese Utility Model Laid-Open No. 59-39876 as a female electrical connector (female terminal) that uses a spring plate having a central portion formed in a mountain shape and has a stopper at the tip. There are different forms.
As shown in FIG. 8, a spring (elastic piece) 20 having a bulging portion 21 formed substantially at the center is formed by folding 22 of the extended tip portion of the bottom wall 24, and the tip portion 23 of the folded spring 20 is formed. It is in contact with the bottom wall 24 and has a stopper piece 26 for stopping the tip of the spring so that the spring 20 does not bend more than a predetermined amount. The spring 20 is used in a state where the spring 20 acts until it abuts on the piece 26.
[0004]
In the female terminal shown in FIG. 8, electrical connection is made by inserting the tongue-shaped male terminal 14 into the tongue-insertion space 27 between the spring 20 and the upper wall 25. At this time, the male terminal The performance and reliability of the electrical connection are determined by the force (contact load) sandwiching 14.
This contact load is determined from the relationship between the spring constant determined by the shape and material of the spring 20 and the amount of displacement of the spring 20, and is in direct proportion to the amount of displacement as shown by the solid line in FIG. is there.
[0005]
[Problems to be solved by the invention]
When designing the female terminal, the spring constant and the amount of displacement are set so as to obtain an appropriate contact load. However, since the thickness of the male terminal 14 is constant, as shown in FIG. The amount of displacement is determined by the gap t between the bulging portion 4 and the conductive plate 2.
[0006]
However, since the female terminal is created by punching and bending with a press, the gap t varies, and the amount of displacement also varies accordingly. As a result, the contact load on the male terminal 14 also varies. This is a variation in fuse performance.
[0007]
The relationship between the variation in the displacement amount and the variation in the contact load is determined by the solid line in FIG. 6 in the conventional product. For example, the variation in manufacturing the terminal gap of ± 0.05 centering on the displacement amount of 0.4 mm (A ), The contact load is between 3.1 and 3.9 kg, that is, a variation (B) of 0.8 kg.
[0008]
In addition, since the reliability of electrical connection is stable when there is a certain contact load, the force required to insert the male terminal when the contact load is set high so that the contact load exceeds a certain value in consideration of variation. There is a problem that the assembly becomes large and the assembly workability deteriorates.
[0009]
In addition, there is a method of obtaining a constant contact load by setting a small spring constant in advance and increasing the amount of displacement, but this may be difficult in terms of space, and a problem may occur when the male terminal is inserted.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention increases the initial spring constant when inserting the male terminal by adding resistance to the sliding of the distal end portion of the spring plate, and thereafter the contact load at a predetermined displacement amount. Is returned to the original spring constant so that the load becomes an appropriate load.
[0011]
That is, according to the present invention , the male terminal 14 is inserted into the tongue piece insertion space 3 of the female terminal having a pair of conductive plates 1 and 2 facing each other, so that the male terminal 14 is sandwiched and electrically connected. In the female terminal of the plug-in fuse, a step 8 having an inclined portion 9 on the entrance side is provided at the back of one of the conductive plate members 1 in the tongue piece insertion space 3 , while the bulging portion 4 is substantially at the center. The spring plate 5 is provided from the inlet side of the plate member 1 toward the inner side so that the bulging portion of the spring plate 5 formed on the tongue piece insertion space 3 faces, and the spring plate 5 can slide. The rear end portion 7 is slid by the insertion-side inclined portion 9 by inserting the male terminal 14 by bringing the rear end portion 7 into contact with the inlet-side inclined portion 9 of the step 8 provided on the inner surface of the plate 1. It becomes a resistance when the spring plate 5 is extended by moving, and the displacement of the spring of the spring plate 5 is The change in the contact load that pinches the male terminal 14 becomes large, and the rear end portion 7 rises along the inlet side inclined portion 9 and advances along the step 8 to thereby displace the spring. A female terminal of a plug-type fuse, characterized in that a change in the contact load with respect to the amount is small .
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 7, the female terminal according to the present invention has a copper alloy female terminal having a pair of left and right tongue insertion spaces 3 connected by a fusing part 15 in the center, mounted in an insulating housing 17. The upper portion is covered with a cover 18 and is used in such a manner that a tongue-like male terminal 14 is inserted into the tongue-piece insertion space 3 from a male terminal insertion hole 19 on the lower surface of the housing.
[0013]
A spring plate 5 having a bulging portion 4 formed substantially at the center is arranged inside the tongue piece insertion space 3 of the female terminal. As shown in FIG. The rear end portion 7 of the plate 5 slides, the spring plate 5 extends, and the male terminal 14 is clamped with a constant pressure.
[0014]
On one inner surface of the female terminal in the tongue piece insertion space 3 at the female terminal, a step 8 having an inclined portion 9 on the inlet side is provided at a position in contact with the rear end portion 7 of the spring plate 5. In this case, the back end 7 slides on the inclined portion 9 of the step 8 to provide resistance when the spring plate 5 extends.
[0015]
The example shown in FIGS. 1 and 2 is a spring plate in which a trapezoidal convex portion is described later as a step 8 at the inner surface of one plate 1 in the tongue piece insertion space 3 by a pair of opposing conductive plates 1 and 2. 5 is formed by pressing so as to correspond to the rear end portion 7 of the plate 5. On the other hand, the bulging portion 4 of the spring plate 5 having the bulging portion 4 formed substantially at the center faces the inner surface of the conductive plate 1. In this way, the inlet-side tip 6 of the spring plate 5 is fixed to the inner surface of the plate 1 by bending or caulking, and the curled slidable back-side tip 7 is provided in correspondence with the back-side tip 7. The trapezoidal convex part 8 is brought into contact with the inlet side inclined part 9.
[0016]
In the female terminal provided with the trapezoidal convex portion 8, as shown in FIG. 5, when the male terminal 14 is inserted into the female terminal which is normally in the state (A), (B) (C) As shown in (d), the distal end portion 7 of the spring plate 5 advances so as to rise along the inlet-side inclined portion 9 of the trapezoidal convex portion 8, and in the states (d) to (e), the trapezoidal convex portion 8 along the upper plane 10.
[0017]
During this time, the displacement amount 0 mm from (a) to 0.3 mm displacement (d) is larger than the original spring constant because the inlet side inclined portion 9 becomes a resistance when the spring is displaced (about 2 in the graph embodiment). 6), and the relationship shown by the dotted line in FIG. 6 is the product 1 of the present invention, and the change in the contact load with respect to the amount of displacement of the spring is large.
[0018]
Thereafter, from the state (d) of the displacement amount of 0.3 mm to the point (e), the distal end portion 7 of the spring plate 5 advances along the upper plane 10 of the trapezoidal convex portion 8. Returning to the spring constant, the relationship shown in the upper part of the dotted line in FIG. 6 is obtained, and the change in the contact load with respect to the amount of displacement of the spring becomes small.
[0019]
Accordingly, as shown in FIG. 6, the spring constant when the male terminal is inserted as described in (d) above should be a spring constant that passes through point P of a contact load of 3.5 kg with an appropriate displacement of 0.4 mm. Even if the manufacturing variation of the terminal gap is the same as the conventional one, the variation of the contact load is small.
[0020]
That is, even if there is a variation of 0.1 mm (A) in the displacement amount of 0.35 to 0.45 mm, the product 1 of the present invention has a contact load of 0.5 kg up to 3.25 to 3.75 kg. To a variation (b).
[0021]
Conversely, if the variation in contact load is made the same as the variation (b) of the product 1 of the present invention, the variation in manufacturing of the terminal gap is 0.06 mm from 0.37 to 0.43 mm of (a). It is necessary to keep it between.
[0022]
As shown in FIG. 4, the step 8 in the tongue insertion space 3 of the female terminal shown in the above-mentioned embodiment is a descending slope 11 in which the back part of the entrance side inclined part 9 is gentle instead of the trapezoidal convex part 8. It can be set as the mountain-shaped convex part 8A of the "he" shape which exhibits.
[0023]
In the case where this “he” -shaped mountain-shaped convex portion 8A is formed on the inner surface of the conductive plate 1, the inlet side inclined portion 9 is resistant to a displacement of 0.3 mm as in the case of the above-described embodiment. Therefore, the spring constant becomes larger than the original spring constant, and the relationship shown by a one-dot chain line in FIG.
[0024]
Thereafter, from the state (d) of the displacement amount of 0.3 mm to the point (e), the distal end portion 7 of the spring plate 5 advances along the gentle descending slope 11 at the depth of the mountain-shaped convex portion 8A. Therefore, the relationship shown by the upper portion of the dashed line in FIG. 6 is obtained, and there is no change in the contact load with respect to the amount of displacement of the spring.
[0025]
Further, the step 8 in the tongue insertion space 3 of the female terminal shown in the above-described embodiment has a stepped convex portion 8B in which the back portion of the inclined portion 9 has a straight stepped shape 12 as shown in FIG. You can also
[0026]
In the case where the step-like convex portion 8B is formed on the inner surface of the plate member 1, the change in the contact load with respect to the amount of displacement of the spring has the same relationship as in the case of the trapezoidal convex portion 8 shown in FIG.
[0027]
【The invention's effect】
In the present invention, even if there is a manufacturing variation in the terminal gap in the tongue piece insertion space of the female terminal, a convex step that becomes a resistance when the spring is displaced is provided. Since the width can be kept small, the female terminal can be easily manufactured, and the performance of the fuse is stabilized.
[Brief description of the drawings]
FIG. 1 is a partially longitudinal side view showing a main part structure of a product of the present invention.
FIG. 2 is a cross-sectional view taken along line XX in FIG.
FIG. 3 is a partial perspective view showing the main part shape of the product of the present invention.
4A and 4B are partial longitudinal sectional views showing the main structure of another example of the product of the present invention, in which FIG. 4A is a side view and FIG. 4B is a partially enlarged view.
FIG. 5 is a partially longitudinal side view showing a relationship between a male terminal insertion state and a spring displacement amount in the product of the present invention.
FIG. 6 is a graph showing the relationship between the contact load and the amount of spring displacement in the product of the present invention and the conventional product.
FIG. 7 is a longitudinal side view of the product of the present invention mounted on a fuse housing.
FIG. 8 is a perspective view of a conventional product.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 2 Conductive board material 10 Upper plane 3 Tongue piece insertion space 11 Down slope 4 Swelling part 12 Straight step 5 Spring board 14 Male terminal 6 Inlet side front end part 15 Fusing part 7 Back side front end part 17 Housing 8 Step 18 Cover 9 Inlet side inclined part 19 Male terminal insertion hole

Claims (4)

By inserting the male terminal (14) into the tongue insertion space (3) of the female terminal having a pair of conductive plates (1, 2) facing each other, In the female terminal of the plug-in fuse to be connected , a step (8) having an inclined portion (9) on the inlet side is provided at the back of one conductive plate member (1) in the tongue insertion space (3). On the other hand, the spring plate (5) is formed on the plate member (1) so that the bulge portion of the spring plate (5) having the bulge portion (4) formed substantially at the center faces the tongue piece insertion space (3). ) From the inlet side toward the back side, and the inlet side inclined portion of the step (8) provided with the slidable back end portion (7) of the spring plate (5) on the inner surface of the plate material (1). (9) to abut against the spring the inlet-side inclined section (9) and the inner side tip (7) is slid by insertion of the male terminal (14) (5) becomes a resistance at the time of extension, and a change in the contact load holding the male terminal (14) with respect to the amount of displacement of the spring of the spring plate (5) becomes large, and the rear end portion ( 7) rises along the inlet-side inclined portion (9) and proceeds along the step (8) so that the change in the contact load with respect to the displacement of the spring is small. A female terminal for plug-in fuses.   The female terminal of the plug-in fuse according to claim 1, wherein the step (8) is a trapezoidal convex portion.   The female terminal of the plug-in fuse according to claim 1, wherein the step (8) is a chevron-shaped convex portion having a "he" shape.   The female terminal of the plug-in fuse according to claim 1, wherein the step (8) is a step-like convex portion.

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